code: def test_loss(self):
      losses = self.head.loss(self.inputs, self.data_samples)
      assert losses.keys() == {
          "triplet_loss",
          "ce_loss",
          "accuracy_top-1",
      }
      assert losses["ce_loss"].item() >= 0
      assert losses["triplet_loss"].item() >= 0
  
file_path: mmdetection/tests/test_models/test_reid/test_linear_reid_head.py
imports: from unittest import TestCase
  import torch
  from mmdet.registry import MODELS
  from mmdet.structures import ReIDDataSample
  from mmdet.utils import register_all_modules
label_desc: Use image node_id 3 for calling the TestLinearReIDHead obj's underlying member method code with example usage: obj.test_loss() without return types